title: Optimization of non-periodic plasmonic light-trapping layers for thin-film solar cells.
abstract: Non-periodic arrangements of nanoscale light scatterers allow for the realization of extremely effective broadband light-trapping layers for solar cells. However, their optimization is challenging given the massive number of degrees of freedom. Brute-force, full-field electromagnetic simulations are computationally too time intensive to identify high-performance solutions in a vast design space. Here we illustrate how a semi-analytical model can be used to quickly identify promising non-periodic spatial arrangements of nanoscale scatterers. This model only requires basic knowledge of the scattering behaviour of a chosen nanostructure and the waveguiding properties of the semiconductor layer in a cell. Due to its simplicity, it provides new intuition into the ideal amount of disorder in high-performance light-trapping layers. Using simulations and experiments, we demonstrate that arrays of nanometallic stripes featuring a limited amount of disorder, for example, following a quasi-periodic or Fibonacci sequence, can substantially enhance solar absorption over perfectly periodic and random arrays.
authors.affiliation: Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.
authors.forename: Ragip A
authors.initials: RA
authors.lastname: Pala
authors.forename: John S Q
authors.initials: JS
authors.lastname: Liu
authors.forename: Edward S
authors.initials: ES
authors.lastname: Barnard
authors.forename: Daulet
authors.initials: D
authors.lastname: Askarov
authors.forename: Erik C
authors.initials: EC
authors.lastname: Garnett
authors.forename: Shanhui
authors.initials: S
authors.lastname: Fan
authors.forename: Mark L
authors.initials: ML
authors.lastname: Brongersma